Air-brake-adjusting device for loaded and empty cars.



A. L. GOODKNIGHT. AIR BRAKE ADJUSTING DEVICE FOR LOADED AND EMPTY CARS.

APPLICATION FILED FEBJQ, 1909.

Patented Dec. 21, 1909.

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A. L. GOODKNIGHT. AIR BRAKE ADJUSTING DEVICE FOR LOADED AND EMPTY CARS.

APPLIOATION FILED IEB.19, 1909.

Patented Dec. 21, 1909.

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ALVA L. GOODKNIGI-IT, OF MENA, ARKANSAS.

AIR-BRAKE-ADJUSTING DEVICE LOADED AND EMPTY CARS.

Specification of Letters Patent.

Patented Dec. 21, 1909.

Application filed February 19, 1909. Serial No. 478,993.

To all whom it may concern:

Be it known that I, ALVA L. GooDKNIGH'r, a citizen of the United States,residing at Mona, in the county of Polk and State of Arkansas, haveinvented certain new and us ful improvements in riir-Brake-AdjustingDevices for Loaded and Empty Cars, of which the following is aspecification.

My invention relates to automatic-airbrake mechanism for railway carsand it is the object thereof to provide an automatically operated meansfor securing greater braking-power on loaded cars than on empty ones.

In automatic-air-brakes as ordinarily arranged the brakes are adjustedso as to secure a certain percentage (in ordinary freight cars about ofthe maximum raking-power obtainable when the car is empty. The maximumbraking power of a car is that obtained when the pressure of thebrake-shoes upon the wheels is just below that sutlicient to lock thewheels and cause them to slide upon the rails, and, in practice, thispressure should never be exeeeeed. Other things being equal, the maximumbraking power of a car is proportional to the load carried upon thewheels and, of course, is greater on loaded cars than on the same carswhen empty. As the momentum of a moving car is proportional to itsweight, it follows that the actual braking power, or the pressure of thebrake-shoes upon the wheels, should be varied proportionally to thetotal weight, or, in other words, that the percentage obtained of themaximum braking power should be the same whether the car is empty orloaded. F or example, a car weighing 30,000 pounds is loaded with aweight of 30,000 pounds, making the total weight on the wheels 60,000pounds. If the brakes were adjusted on the car when empty so as toobtain 70% of the maximum braking power, then when the car was loadedthe braking power would be only 35% of the maximum, and as the momentumof the moving car is proportional to the weight thereof, the loaded carwould be far more ditlicult to stop than the empty car.

To show the effect in the operation of a train of cars having varyingpercentages of braking power, consider the case of a train consistingpartly of loaded cars and partly of empty ones, in which all the carshave the same percentages of braking power when empty. If the loadedcars are near the rear end of the train, when the brakes are applied theempty cars, having the higher percentage of braking power and tending tostop more quickly than the loaded cars, will be pushed forward by theloaded cars, and a sutlicient application of the brakes to stop thetrain quickly will often result in overbraking of the empty cars withconsequent flattening of the wheels thereof resulting from sliding thesame upon the rails. In case the loaded cars were at the head of thetrain and the empty cars behind them, application of the brakes willcause the empty cars to hold back on the loaded cars and, in practice,such action frequently results in breaking the train in two, withconsequent damage to the dratt-rigging of one or more of the cars.Theoretically then, if a car is doubled in weight by loading the same,the actual braking power, or the pressure of the brake-shoes upon thewheels, should be doubled in order that the braking power may beproportional to the momentum of the car and the loaded car stopped withthe same facility as the empty one.

In air-brakes controlled by the ordinary types of triple-valves, thebrake-cylinderpressure, and consequently the pressures of thebrake-shoes upon the wheels, is proportional to the travel of thebrake-piston, since the movement of the triple-valve is controlled bythe relation of train-pipe-pressure and auxiliary reservoir pressure.Thus a certain reduction of train-pipe-pressure will actuate thetriple-valve and admit a quantity of air to the brake-cylindersufficient to cause a reduction of pressure in the auxiliary reservoircorresponding to the reduction of train-pipe-pressure. The quantity ofair admitted to the brake-cylinder is substantially the same whether thepiston travel is long or short, since the admission of air thereto isstopped by the triplevalve as soon as the auxiliary-reservoir-pressureis reduced by an amount proportional to the re duction oftrain-pipe-pressure. It follows that if the piston travel is short theair admitted to the brake-cylinder will have only a limited space inwhich to expand and consequently will be at a higher pressure than ifthe piston travel were longer and a larger space formed thereby in thebrake-cylinder in which the air admitted thereto might expand.

all

The piston travel is determined by the amount of slack in the brakeconnections, or the distance from the wheels to the brakeshoes when inrelease position, assuming that there are no loose joints or lost motionin the connections between the brake-cylinder and brake-shoes.

From the foregoing it will be obvious that by providing meansautomatically varied by the loading of the car, for changing the travelof the brakepiston, or rather for changing the amount of slack in thebrake connections, the braking power of a car may be automaticallyvaried to correspond with the loading of the car.

My invention provides such a means for varying the braking power of acar, and constructions embodying my invention are illustrated in theaccompanying drawings, in which Figure 1 is a diagrammatic plan view ofthe brake connections of a car in the positions assumed on an empty carwhen my adjusting device is used in connection therewith, Fig. 2 is asimilar view showing the positions of the connections when the car isloaded, Fig. 3 is a tansverse vertical section of one of the car-trucks,showing my mechanism thereon, Fig. 4 is a detail plan view of a portionof the same, Fig. 5 is a longitudinal vertical section of the truck,showing the position of the fulcrum-adjusting lever on an empty car, andFig. 6 is a similar view showing the position of said lever on a loadedcar.

Referring to Figs. 1 and 2, the parts of an ordinary system of brakeconnections are shown in the positions assumed thereby when the brakesare applied, in the first figure as adjusted by my mechanism on an emptycar,

and in the second figure as automatically adjusted on a loaded car. Asthe function and operation of the parts will be understood by thoseskilled in the art, I will merely enumerate the different parts shownand indicate the same by reference numerals, as follows: Thebrake-cylinder 1, the piston rod 2, the cylinder-lever 3, the hand-brakerod 0, the floating-lever 1, the floating-lever connecting-rod 5, thelive-levers 6, the livelever connecting-rods 7, the dead-levers 8, thedead-lever connecting-rods 9, the brakebeams 10, the dead-leverfulcrum-rods 11, the brakeshoes 12, and the wheels 13. In all ordinarysystems of brake connections the deadlever fulcrum-rods are connecteddirectly with the truck-frame, and adjustments of the dead-lever fulcrumare made to change the slack of the brake-connections and to compensatewear of the brake shoes, by connecting the end of the dead-lever withdifferent ones of a series of holes in the free end of the fulcrum-rod.

In carrying out my invention, instead of connecting the dead-leverfulcrum-rod direct-ly to the truck-frame, I connect the same with theadjusting-lever 1 1 which is fulerumed on a bracket and is adapted toswing on said fulcrum from the position shown in Fig. 5 to the positionshown in Fig. 6. The bracket 15 is secured to one of the transoins 16 ofthe truck-frame, and has two vertically-extending guide-slots 17 formedtherein, one on each side of the fulcrum of the adjusting-lever 1e, asshown in said Figs. 5 and 6. A. block or head 18, provided with rollers19 at the sides thereof, is arranged in one of the guide-slots in thebracket. The said head is connected by means of bolts 20 to the end ofthe transomlever 21 which is fulcrumed on the transom 16 near the endthereof opposite the bracket 15. The said lever and bracket are soarranged longitudinally of the truck that by reversing the position ofthe head 18, as shown by dotted lines in Fig. at, the same may be placedin either of the guide-slots 17 and connected with the transom-lever 21on the front or rear side thereof by said bolts 20. Near the fulcrum ofthe transom-lever 21 the depressing-bar 22 is connected therewith Thesaid bar extends upwardly through a guide-bracket carried by the transom16, and is connected with the bolster 24: which rests on the springs 25and supports the body-transtnn 26.

When the car is loaded, the trucksprings 25 are compressed and thebolster 24. moves downwardly relatively to the rest of the truck-frame.211, being communicated to the transom-lever 21 through thedepressing-bar 22, moves said lever 21 and the head 18down to thepositions shown in Figs. 3 and 6. The downward movement of the head 18act-uates the lever let, throwing the same to a substantially verticalposition, as shown in Fig. 6, and said movement of the adjusting-lever,by changing the fulcrum of the dead-lever, reduces the slack of thebrake connections. bringing the brake-shoes closer to the wheels, sothat when the brakes are applied the piston-travel necessary to makesuch application is relatively short, indicated in F 2.

lVhen the load is removed from the and the truck-springs expand andraise bolster 2t relatively to the transoms, the head 18 is raised tothe upper end of the guide-slot 17, and the adjusting-lever is therebypermitted to move over to the diagonal position shown in Fig.5, thusincreasing the amount of slack in the brake connections so that a longerpiston-travel is necessary to apply the same, as indicated in Fig. 1.

The lever 21 is employed in connecting the head 18 with the bolster 24,for the purpose of increasing the amount of movement obtained directlyfrom the compression of the car the This movement of the bolstertruck-springs by the loading of the car. From Fig. 6 it may be seen thatafter the adjusting-lever 14 is raised to the vertical position bymovement of the head 18 to a position below the fulcrum of saidadjusting-lever, the said head may have a considerable vertical.movement in the guideslot 17 without permitting the adjustinglever tochange from the vertical position. This additional vertical movement isallowed to the head to compensate for the variations in the compressionof the trucksprings resulting from jolting over rough tracks and thelike, so that such variations of the spring compression will not alterthe adjustment of the brakes.

The head 18 is made reversible with r spect to the transom-lever 21, andthe extra guide-slot 17 provided in the bracket adacent to the fulcrumof the adjusting-lever, in order to enable the same devices to be usedfor any system of brake connections in which it might be necessary. inorder to increase and decrease the slack of the connections, to move thedead-lever fulcrum in directions opposite to those necessary in thesystem of connections shown.

N ow, having described my invention, what i claim and desire to secureby Letters Patent is:

1. In an automatic-air-brake mechanism for railway cars, the combinationwith a rod-and-lever system connecting the brakecylinder andbrake-shoes, of means con nected with said rod-and-lever system andautomatically operated by compression and expansion of the truck-springsfor varying the relation of the brake-shoes and the wheels or the car,the said varying means operating to retain the brake-shoes close to thewheels when the trucksprings are compressed beyond a predeterminedamount and to leave the brake-shoes more distant from the wheels whenthe truck-springs are not compressed beyond said predetermined amount.

2. In an automatic-air-brake mechanism for railway cars, the combinationwith the means for connecting the brake-cylinder and brake-shoes, or alever connected with said connecting means, said lever being arranged sothat movement thereof will vary the relation of the brake-shoes and thewheels of the car, and means for automatically actuating said lever bythe compression and eX- pansion of the car-truck springs, the saidactuating means operating the lever to retain the brake-shoes close tothe wheels when the car-truck springs are compressed beyond apredetermined amount and to leave the brake-shoes more distant from thewheels when said springs are not compressed beyond said predeterminedamount.

3. In an automatic-air-brake mechanism for railway cars, the combinationwith the means connecting the brake-cylinder and brake-shoes, of a leverarranged with said connecting means so that movement of said lever willvary the relation of the brakeshoes and the wheels of the car, and meansfor actuating said lever, said actuating means being controlled byrelative movement of r the truck-holster and transom and operating toretain the brake-shoes close to the wheels when the truck-bolster isdepressed beyond a predetermined amount and to leave the brake-shoesmore distant from the wheels when the truck-bolster is not depressedbeyond said predetermined amount.

at. In an automatic-air-brake mechanism for railway cars, thecombination with the mechanism connecting the brake-cylinder andbrake-shoes, of a lever arranged with said connecting mechanism so thatby movement of said lever the brakepiston-travel necessary to apply thebrakes will be varied, and means automatically controlled by the loadingor the car for actuating said lever, said means operating to require ashort brake-piston-travel when the car is loaded beyond a predeterminedamount and to per mit a longer brake-piston-travel when the car is notloaded beyond said predetermined amount.

5. In an automatic-airbrake mechanism for railway cars, the combinationwith the mechanism for connecting the brake-cylinder and brake-shoes, ofa lever arranged with said connecting mechanism so that by move ment ofthe said lever the slack between the brake-shoes and car wneels may bevaried, and means controlled by the loading of the car for actuatingsaid lever, the said actuating means operating to cause a minimum amountof slack when the car is loaded beyond a certain minimum and to permitan increased slack hen the car is not loaded beyond said minimum.

6. In a railway car, an automatic-air-brake mechanism comprising thecombination with a brakecylinder, brake-shoes, and mechanism connectingthe same, of a means arranged in said connecting mechanism and bymovement of which the slack between the brake-shoes and the car wheelsmay be varied, and means automatically controlled by the loading of thecar for actuating said slack-varying means, the said actuating meansoperating to cause a minimum amount of slack when the car is loadedbeyond a certain minimum and to permit an increased slack when the caris not loaded beyond said minimum.

7. In an automatic-air-brake mechanism for railway cars, the combinationwith mechanism for connecting the brake-cylinder and brake-shoes, of alever connected with said connecting mechanism and movable to twopositions in one of which the connecting mechanism is caused to hold thebrake-shoes close to the wheels and in the other to hold the brake-shoesmore distant therefrom, and means for moving the lever to and retainingthe same in the first position when the car is loaded.

8.111 a railway car, an automatic-airbrake mechanism comprising thecombination with the brake-cylinder, brake-shoes and mechanismconnecting the same, of a lever arranged with said connecting mechanismand by movement of which the slack between the brake-shoes and car wieels may be varied, and means for actuating said lever comprising ahead movable adjacent to said slack-varying lever, a lever connectedwith said head and fulcrumed on the cartruck transom, and a barconnected with said transom-lever and with the truck-bob ster, wherebyrelative movement of the bolster and transom will actuate the head.

9. In an antomatic-air-brake mechanism for railway cars, the combinationwith the car-truck, brake-cylinder, brake-beams, and equalizingrod-and-lever connections between the brake-cylinder and brake-beams,including a dead-lever connected with one of the brake-beams, of anadjusting-lever connected with the dead-lever fulcrum-rod, and meanscontrolled by compression and expansion of the truck-springs foractuating said adjusting-lever to vary the dead-lever fulcrum.

10. In an autoinatic-air-brake mechanism for railway cars, thecombination with the car-truck, bral:ecylinder, brake-beams, andequalizing rod-and-lever connections between the brake-cylinder andbrake-beams, including a dead-lever connected with one of thebrake-beams, of an adjusting-lever connected with the dead-lever fulcrumso that by movement of said lever the deadlever fulcrum may be varied,and means for actuating said adjusting-lever, said actuating means beingcontrolled by the loading of the car.

11. In an auto1natic-air-brake. mechanism for railway cars, thecombination with the car-truck, brake-cylinder, brake-beams, andequalizing rod-and-lever connections between the brake-cylinder andbrake-beams, including a dead-lever connected with one or thebrake-beams, of an adjusting-lever connected with the dead-lever fulcrumso that by movement of said adjusting-lever the dead-lever fulcrum maybe varied, a head movable adjacent to the said adjusting-lever foractuating the same, a lever fulcrumed on the car-truck transom andcarrying said head, and a bar connected with said transom-lever and withthe truck-bolster whereby movement of the bolster relatively to thetransom will actuate the adjusting-lever.

12. In an automatic-air-brake mechanism for railway cars, thecombination with the car-truck, brake-cylinder, brake-beams, andmechanism connecting the brake-cylinder and brake-beams, of a barconnected with the truck-bolster, a lever fulcrumed on the truck-transomand connected with said bar, an adjusting-lever fulcrumed on thetruckframe, means operatively connecting said levers whereby movement ofthe bolster relatively to the transom will actuate the adjusting lever,and means connecting the said adjusting-lever and brake-connectingmechanism, whereby movement of the adjustinglever will vary thebrake-piston travel necessary to apply the brakes.

In testimony whereof I have hereunto subscribed my name in the presenceof two witnesses.

ALVA L. GOODKNIGHT. Vitnesses D. O. BARNELL, ROY G. KRATz.

